The effects of marijuana on female reproductive physiology are unknown. Although some animal studies indicate a variety of neuro-endocrine abnormalities and possible teratogenicity, no controlled study has been reported in humans. Since quantitative assessment to support anecdotal information is now possible by our separate assays for delta 9-THC, the psychoactive ingredient of marijuana, and its metabolites, we have undertaken a prospective study of the effects of marijuana on women. Female marijuana users (250 pregnant and 1000 non-pregnant) will be compared to non-user groups. Menstrual irregularities and other abnormalities of reproductive physiology will be investigated in non-pregnant females. Antepartum, labor, delivery and neonatal problems will be compared in marijuana users and matched controls. The newborns will be analyzed by normal pediatric milestones for at least 18 months. In all phases of the work, anecdotal clinical data will be weighed against accurate laboratory measurements. The results should permit an unbiased evaluation of immediate and long-term marijuana effects on female reproductive physiology.